Help please

bernard0368

My 40D has stopped recgonising my canon lens (all of them) but works fine with my sigma and tamron. nothing happens when I press the shutter, no error message or anything. i have taken the batteries out cleaned the contacts but still no Joy. Has anyone got any ideas?

Rainbowsend

I dont have a Canon but if you are not getting any
error message it sounds like it is a contact problem,
I presume you have tried cleaning both sets of contacts,
the camera and lens? Also make sure the batteries are
fully charged, I know it sounds silly but sometimes that
would make a difference, though if your other lenses are
working ok?? Sorry not much help.

zerohamster

try cleaning the contacts on the camera with a rubber eraser for pencils. be careful not to bend them though.
I believe the tamron and sigma lenses work because they use a higher voltage to transfer info and therefore still work when the contacts are oxidised.
The rubber eraser will remove the oxidisation and it should do the trick. If that doesnt work then let me know and I will see if I can help.

Best of luck!

cnocbui

Do you have to put batteries in Tamron and Sigma lenses?

zerohamster

cnocbui wrote: »

Do you have to put batteries in Tamron and Sigma lenses?

no they dont need batteries, just the circuitry isnt as sensitive to a change in current/voltage from the oxidisation.

bernard0368

Thanks Zerohamster,
I had cleaned the contacts but not using a eraser, I will get one this morning and try same. The fact that both the other lens worked had me confused. I will let you know what happens.

zerohamster

bernard0368 wrote: »

Thanks Zerohamster,
I had cleaned the contacts but not using a eraser, I will get one this morning and try same. The fact that both the other lens worked had me confused. I will let you know what happens.

I hope it works for you. the only thing that is odd is that the camera wont display an error 99 with the canon lenses which would normally happen with oxidisation. Also clean the lens contacts with the rubber too as that would add to the fault if they were oxidised too.
If the cleaning doesnt work and its a hardware fault then I do repairs if you would like me to check it out and fix it. Im based in Greystones if you are near.

bernard0368

Thanks Zerohamster,
I got this sorted it was the tamron any time I attached it to the camera it caused the problem. I am not sure why but after I took all the batteries out and let it sit for ten minutes attached the canon lens it worked fine but as soon as I put the tamron on it all started again.
I have contacted tamron as the lens is still under warranty and wait to see what they say.

zerohamster

No problem, sorry I couldnt help more
Out of curiosity what lens is it that is causing the problem?
let us know what they say, I would be curious to know what the fault is if it is the lens causing the problem and not some odd fault on the body.
cheers